Where Does Snow Come From?

The flip answer these days would be, "It's shot from guns; snowguns, that is."

A more science-based answer comes from meteorologist Jeremy Davis.

"Up in the upper levels of the atmosphere, there are super-cooled water droplets, which can exist as water at very low temperatures, even zero degrees Fahrenheit. Water can stay unfrozen at that temperature if it's superfine," Davis told OnTheSnow.

"A couple of the very fine droplets will collide and merge, forming a little ball of ice, then more of the droplets will hit that ball, and freeze immediately into a crystalline structure. The structure becomes too heavy, and starts to fall, picking up more of the tiny droplets, forming clumps, and this is the snow that we see falling," Davis said.

All snow, he said, begins as the very fine droplets of super-cooled water.

They can show up as rime ice on rocks and branches on mountain tops; become lake effect snow or ocean effect snow that happens when really cold air moves across warmer waters; convective snows, which are similar to summertime thunderstorms that occur when rising air masses run into colder air higher up; pogonips or ice fog that forms when bitter cold, moisture-laden air is trapped close to the ground by an overlying warm air mass; Nor'easters that hit New England and other parts of the U.S. East Coast and cause some of the heaviest snowstorms; and snow squalls that can drop an inch or two of snow ahead of a cold front in a few minutes time.

Davis recalls losing his '87 Nissan Maxima when such a snow squall coated a road in Northern Vermont, he started to slide, hit his brakes and was in turn slammed into from behind by another driver, with the impact slamming him into one of the stone walls for which New England is famous.